That's good news, i would love to see this featured since there are tons of usefull UX

I already modified my deployed code and successfully included the filtering option on my grid. In the meantime, is there some nifty way to push in the code in after deploying from Designer, or use an override like in this post?

We are finalizing the spec to expose the proper APIs and working with component authors to ensure that we can support the various different situations that people have implemented UX's out there.
This will be a feature of Designer 2.x.

Very good news!

I have a bunch of components of mine (simple but useful) I would like to use in the Designer. I also use some ux components from ExtJS out of the box and some extended by other guys.